// Copyright © 2019 NAME HERE <EMAIL ADDRESS>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package cmd

import (
	"fmt"
	log "github.com/sirupsen/logrus"
	"github.com/spf13/cobra/doc"
	"os"

	"github.com/mitchellh/go-homedir"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var cfgFile string

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
	Use:   "demo",
	Short: "A brief description of your application",
	Long: `A longer description that spans multiple lines and likely contains
examples and usage of using your application. For example:

Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.`,
	// Uncomment the following line if your bare application
	// has an action associated with it:
	//	Run: func(cmd *cobra.Command, args []string) { },
	SuggestionsMinimumDistance: 1,
	DisableSuggestions:         false,
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	if err := rootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	// Here you will define your flags and configuration settings.
	// Cobra supports persistent flags, which, if defined here,
	// will be global for your application.
	rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.demo.yaml)")

	rootCmd.PersistentFlags().StringP("author", "a", "YOUR NAME", "Author name for copyright attribution")

	// bind global flags to viper
	viper.BindPFlag("author", rootCmd.PersistentFlags().Lookup("author"))
	// set viper default value
	viper.SetDefault("author", "NAME HERE <EMAIL ADDRESS>")

	// Cobra also supports local flags, which will only run
	// when this action is called directly.

	// go run main.go  --toggle --name 张三
	s := rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
	log.Infoln("toggle: %+v", *s) // toggle: false

	name := rootCmd.Flags().StringP("name", "n", "default Name", "Help message for toggle")
	log.Infoln("name: ", *name) // name: default Name

	rootCmd.Run = func(cmd *cobra.Command, args []string) {
		// global : PersistentFlags 获取方式
		// 1. 不需要 BindPFlag,直接获取
		author, _ := rootCmd.PersistentFlags().GetString("author")
		log.Infoln("output:author from `PersistentFlags`", author)
		// 2. 需要 BindPFlag
		log.Infoln("author from `viper`", viper.GetString("author"))

		// local flag:只能在当前 command 中的 Run 里面使用
		toggle, err := cmd.Flags().GetBool("toggle")
		log.Infoln("toggle =", toggle, " err=", err) // toggle = true  err= <nil>
		log.Infoln("name =", *name)                  // name = 张三

		if len(args) <= 0 {
			cmd.Help()
			return
		}

	}
	//general ways:
	err := doc.GenMarkdownTree(rootCmd, "./doc")
	if err != nil {
		log.Fatal(err)
	}
	/**
	Example:
	go run main.go  --toggle --name 张三
	debug:=== > toggle: false
	debug:=== > name:  default Name
	output:toggle = true  err= <nil>
	output:name = 张三
	*/
}

// initConfig reads in config file and ENV variables if set.
func initConfig() {
	if cfgFile != "" {
		// Use config file from the flag.
		viper.SetConfigFile(cfgFile)
	} else {
		// Find home directory.
		home, err := homedir.Dir()
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		// Search config in home directory with name ".demo" (without extension).
		viper.AddConfigPath(home)
		viper.SetConfigName(".demo")
	}

	viper.AutomaticEnv() // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Println("Using config file:", viper.ConfigFileUsed())
	}
}
